Due to the increased population in the world, the noise generated by the testing of large caliber weapon systems in communities located near testing facilities of such weapon systems is becoming an increasing problem. As a result of this concern in noise, there has been a need for a gun muffler to attenuate the generated noise level. Preferably, such a gun muffler should be able to rapidly and safely attenuate the noise generated by the firing of a projectile by a large caliber gun.